Electronic counter



May 6, 1952 w. A. GEOHEGAN ELECTRONIC COUNTER 4 Sheets-Sheet 1 FiledApril 13, 1946 NVE NTOR ET??? Ls I I E 1 1 EEEEEEEEE} y 6, 1952 w. A.GEOHEGAN 2,595,519

ELECTRONIC COUNTER v Filed April 13, 1946 4 Sheets-Sheet 2 I N V EN TOR.J. 60 flizzlm w m m 1m QQ A TTORNE Y.

May 6, 1952 Filed April 13, 1946 W. A. GEOHEGAN ELECTRONIC COUNTER 4Sheets-Sheet 5 SOVOLTS INVENTOR.

ATTORNEY.

W. A. GEOHEGAN ELECTRONIC COUNTER May 6, 1952 4 Sheets-Sheet 4 FiledApril 15, 1946 Patented May 6, 1952 UNITED STATES FATENT QFFICEELECTRONIC CGUNTER William Anthony Geohegan, Larchmont, N. Y.

Application April 13, 1946, Serial No. 662,038

M-Claims. 1

My invention relates to processes and apparatus for electronic counting.

The subject matter relating to the presettable predetermined countregister, originally contained in this application, forms the subjectmatter of my divisional application, Serial No. 789,176, filed December2, 1947, now abandoned, for register and process.

A purpose of my invention is to simplify, reduce the size, reduce thecost, reduce the number of electronic tubes and improve the reliabilityand efficiency of electronic counters.

A further purpose is to employ gas tubes, suitably gas filled glowdischarge lamps such as neon or argon lamps, to function actively in anelectronic counting ring, such as a decade, and not merely asindicators.

A further purpose, in an electronic counter having a counting ring, isto employ a device having a sharp voltage point at which current ceasesto flow or a sharp cut-off, in each unit of the counting ring, and toutilize this device when it is conducting to prevent any other device inother units of the ring fromconducting at the same time, and desirablyalso for rendering the device in the next unit conducting when the nextimpulse is received to be counted. The device having a sharp voltagepoint at which current ceases to fiow, or a sharp cut-off, will mostdesirably be a gas tube Such as a gas filled glow discharge lamp, but itmay also be a rectifier and associated resistors as later explained. Asuitable rectifier may be a vacuum tube (diode), a copper oxiderectifier, a selenium rectifier or a crystal detector. Whenever hereinreference is made to such a gas tube, it is intended that any otherdevice having a sharp voltage point at which current ceases to flow maybe used.

A further purpose is to employ in an electronic counter a counting ringhaving a gas tube Or the like in each unit, and, when any gas tubestrikes, to use this striking not merely to indicate the count but toprevent any other gas tubes in the other units of the ring fromstriking, preferably by voltage transmitted from the gas tube which hasstruck through preferably substantially equal resistors to each otherunit, and desirably also to transmit through the struck gas tube to thenext unit of the ring the next impulse to be counted so as to strike thenext gas tube.

A further purpose is to employ, in a counting ring, an amplifier havinga control grid and a gas tube or the like, in each unit, to preferablyindicate the count by the striking of a particular gas tube, to applythe voltage due to the current in the particular gas tube to eachamplifier other than the one in that unit, to amplify the voltage ineach other amplifier, to apply this amplified voltage to each gas tubeother than the one conducting to prevent striking of any other gas tube,and upon receipt of an impulse to be counted desirably to apply thatimpulse to the control grid of the amplifier in the next unit inamplified and preferably inverted form with respect to any impulseapplied to the control grid of any other amplifier to cause theamplifier in the next unit to gain and strike the gas tube in that unit.

A further purpose in electronic counting, using a counting ring havingan amplifier with a control grid and a gas tube or the like, in eachunit, is to strike one gas tube, at the same time to raise the potentialof all other control grids in the ring in a positive direction and alsoat the same time to reduce the potential of all other gas tubes belowtheir striking voltages, and upon receipt of the next impulse to becounted desirably to raise the potential of the next gas tube above itsstriking voltage.

A further purpose is to form an electronic counting ring of unitsoperatively interconnected and each including a gas tube, the gas tubein each unit having an open circuit condition in which it is inactiveand a closed circuit condition in Which it conducts current to everyother unit of the ring to prevent the gas tubes in such other units fromstriking, desirably indicates the count on the ring and desirablytransmits to the next unit the impulse advancing the count.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate one main form of myinvention, with variations, the main form and variations being chosenfrom the standpoints of convenience in illustration, satisfactoryoperation and clear demonstration of the principle involved.

Figure 1 is a diagrammatic illustration of the circuit of a countingring, in the particular case a decade, in accordance with the invention.

Figure l is a fragmentary circuit diagram showing a variation in Figure1.

Figure 2 is a diagram of a circuit including several decades and arelay.

Figure 3 is a fragmentary circuit diagram showing means for passing onthe impulse to the next counting ring.

Figure 4 is a circuit diagram showing a variation in the counting ring.

In the drawings like numerals refer to like parts.

The electronic counter of the present invention indicates directly thenumber of impulses that have been received. It also, where desired,operates any suitable device when a predetermined number of impulses hasbeen received. When controlled by a phototube or other light-sensitivedevice, it may be used to count the number of objects passing a givenpoint. It may also be used to reduce impulse frequency to any desiredextent, or, in conjunction with an oscillator or other impulse generatorof known frequency, it will measure time intervals. Other usefulapplications will be readily apparent to those skilled in the art.

By the present invention a simplification over prior art countingcircuits is achieved by using gas filled glow discharge lamps (neon orargon lamps) or other devices having a sharp voltage point at whichcurrent ceases to flow or a sharp cut-off, such as other gas tubes, orrectifiers with associated resistors, such as vacuum tube rectifiers(diodes), copper oxide rectifiers, selenium rectifier-s, or crystaldetectors, as functional components of the counting circuit. In priorcounting circuits, such neon lamps have been used merely as indicatorsto show the count, but the lamps did not function in connection with theoperation of counting. In fact they were apt to cause error bygenerating unwanted impulses when they struck.

In the present invention I preferably combine the electricalcharacteristics of such neon lamps with the characteristics ofconventional vacuum tube amplifiers in order to produce a simplercounting circuit than those of the prior art Without sacrificingperformance and convenience in operation or in reading. A furthersimplification is accomplished by using the same neon or other gas lampsas indicators and operating elements of the circuit.

The invention may be applied to any counting rings, but it is preferredto use the decade or scale of ten type, and this form has beenillustrated. The ring will, however, operate with a larger or smallernumber of units than ten.

The decade counter counts on the decimal system, and employs one or moredecades or counting rings each of which requires ten impulses to advanceit through its entire cycle and return it to its original or zeroposition. At the time it completes its cycle or returns to zeroposition, it generates an impulse which advances the succeeding decadeby one step. In the preferred embodiment, a decade has ten indicators,one being energized at each unit of the count, but

in some cases the decade may be blind or nonindicating.

Thus in the preferred form, where neon lamps are used as indicators, andare numbered to "9 inclusive, where five impulses have been received,number lamp in the first or units decade will be struck or lit, andnumber 0 lamps will be lit in all other decades. Where used herein, theterm struck is used to indicate that the lamp lights and remains lighteduntil a further described change occurs in the circuit.

Again when forty impulses have been received, the units decade will havemade four complete cycles, and its number 0 lamp will be struck, Whilethe tens decade will have received one impulse for each complete cycleof the units decade, and its number 4 lamp will be struck. Thus thecounter will directly read forty.

In the accompanying drawings, certain electronic tubes and impedancesare illustrated, and

in several cases, to aid the user, I have given examples of tube typesand impedance dimensions. It will be understood that these are stated inillustration but not in limitation, and that changes and readjustmentsin tube types and impedance dimensions may readily be made by thoseskilled in the art without departing from the spirit of the disclosure.

Figure 1 illustrates a counting ring, which in this case is a decade,consisting of ten units numbered respectively from 0 to 9 inclusive.Each unit consists of its electronic elements and associated impedances,constituting an operative unit to receive, respond to and usuallyindicate the counting impulse, and pass along the succeeding impulse tothe next similar unit. It will be evident that this is truly a ring inthe sense that not only does number 1 follow number O," etc., but alsonumber 0 follows number 9.

It will also be evident that auxiliary effects may occur when the ringcompletes a cycle, such as the actuation or advance of another countingring, but for the moment in considering the counting ring as an entitythese features are eliminated from the discussion.

It will also be understood that means may be provided for resetting thecounting ring or interconnected group of counting rings to zero at anydesired time, and that, as later explained, external effects may be setin motion upon attaining any particular count.

Each unit of the ring includes a device having a sharply defined voltagebelow which current ceases to flow, which in the preferred embodimentwill be a gas tube. suitably a cold cathode gas filled glow dischargelamp, such as for ordinary purposes a small commercial neon or argonfilled lamp. It will also be evident that the device having sharpcut-off may be a rectifier, with associated resistors, such as a copperoxide or selenium rectifier or a crystal detector or preferably a vacuumtube diode rectifier.

Since for best operation a gas tube will be used as a device havingsharp cut-oil, Figure 1 illustrates tubes of this character used forthis purpose.

The individual gas tubes in the individual units are indicated at.25 to34 inclusive, the terminals 35 of the gas tubes being suitably identicaland capable of connection with either side of the tube on the highvoltage side. Also employed in each unit is an individual amplifier 36to 45, inclusive, which in the particular embodiment shown is a triodehaving a cathode 45, anode 41 and control grid 48. For convenience, twintriodes such as SJ 6 or 7F? are shown in which two amplifiers are placedin a single envelope, but it will be evident that this may not in allcases be necessary or desirable. It will further be evident that while Ihave shown triodes, other tube constructions, such as pentodes may beemployed.

For convenience the cathode heater and heater circuits which will beused have been omitted from the drawing.

Energy actuation of the units is accomplished by a direct current sourcehaving its positive side above ground connected at 49 and its negativeside at ground connected at 50. The lead 49 provides positive voltageconnection to all units of the ring and is connected to all anodes 47through suitable substantially equal anode load resistors 5|, one ineach unit of the ring. Without attempting to limit to a particularvalue, it may be stated that good results have been obtained using anapplied voltage of approximately 5 350 volts and a resistance ofapproximately 0.24 megohm in the anode load resistors.

The cathodes 43 are connected together at 52 and connected to groundthrough the cathode bias resistor 53, which in the preferred embodimentof my invention may have a resistance of approximately 500 ohms.

In each unit, the device having sharp cut-off, in this case a gas tube,is connected at 54 to the anode of the amplifier of that unit, thusapplying higher voltage to the terminal of the gas tube to which thisconnection 54 is made. It wili noted that elsewhere this terminal willbe referred to as the higher voltage terminal of the gas tube or otherdevice having sharp cutoff.

The lower voltage terminal of each device .-aving sharp cut-off (gastube) is connected at to ground through one of the preferablysubtantially equal resistors 56, which in the preierred embodimentdesirably has a resistance of approximately 0.24 megohm. The lowervoltage terminal of each device having sharp cut-off (gas tube) is alsoconnected through one of the preferably substantially equal resistors 57to the control grid of the amplifier of each other unit in the ring, butnot to the amplifier of the unit containing the particular gas tube. Inthe number unit these individual resistors are designated 5V, 51 to 51*,inclusive, and it will be understood that in each other unit there willbe an individual resistor between the lower voltage terminal of the gastube or other device having sharp cut-of? and the control grid of eacharmplifier other than the amplifier in that unit.

For best results the resistors 57 should be substantially equal andshould have in the preferred embodiment a resistance of approximately4.7 megohms.

Between the lower voltage terminal of each device having sharp cut-offand the control grid of the next amplifier in the sequence of counting,I also interpose in series connection a resistor 58, preferably having aresistance of approximately 2.2 megohms, and a capacitor 59, preferablyhaving a capacity of approximately 100 micro-microfarads.

The impulse to be counted, which may of coursebe transmitted from apreceding counting ring or from a suitable impulse circuit, will bereceived at the terminal 63 and transmitted through individual resistors(ii, suitably each having in the preferred embodiment resistances ofabout 4.7 megohms, to the individual control grids of the amplifiers ofeach unit in the ring. The input terminal 6!) is also connected toground through a resistor 62 preferably having a value of approximately.51 megohm.

It will be understood that with reasonable matching, the values of theimpedances mentioned can be varied widely, and that the particularvalues givenare stated for convenience of those who may construct thedevice and because the values given fit in with standard resistancesizes which are available on the market.

It will be understood that impulses of widely variant character may becounted, provided they are passed through a suitable input circuit whichwill convert them to nearly uniform impulses to be applied at theterminal 63. It will also be understood that as well known in the art,means may be used to amplify and shape the pulses to the mostadvantageous form for counting in the ring. It will also be evident thatthe original impulses may be used to trigger impulses of the preferredcharacter for counting. All impulses received by the counting ring willbe positive and preferably of about 0.1 millisecond duration, and

preferably of the order of volts in amplitude. The decade will functionto count such impulses with a high degree of accuracy, and. at speeds ashigh as about 1000 per second with the particular impedance valuesgiven.

The amplifiers and gas tubes operatively interconnected as shown inFigure 1 with the impedances illustrated, form a system such that in astable state at least one gas tube or other device having sharp cut-offwill be conducting (striking or lighted in the case of the gas tube),whereas no more than one can be conducting at a given time.

If none of the devices having sharp cut-offs were conducting, all of thecontrol grids would be at approximately zero or ground potential, all ofthe anodes would be regulated by the cathode bias resistor 53 to avoltage of approximately 160 volts in the example given, and all of thedevices having sharp cut-off (gas tubes) would tend to become conducting(strike). When the device isfirst turned on, and before any impulse tobe counted arrives, the conducting tube may be any one of the ten. Thecounting ring may then be set to zero by suitable means such as thosedescribed below (closing contacts 82 by relay SE in Figure 2). As soonas one of these devices becomes conducting (strikes) the current flowingthrough it develops a positive voltage at its lower voltage terminal 55and applies this voltage through one of the resistors 57 to the controlgrid of each amplifier in the other units, but not to the amplifier inits own unit. This positive voltage applied to the control grids of theother amplifiers causes all of such amplifiers to draw more current andlowers the voltage applied across each of the other devices having sharpcutoff (gas tubes) to a value below the voltage which will maintainconduction, thus preventing the gas tubes from striking where gas tubesare used. At the same time it will be evident that the potential of thecontrol grid of the amplifier in the unit having the conducting gas tubeor other device having sharp cut-off will be very slightly influenced,since there is no resistor connecting this gas tube to the control gridof its own amplifier. At equilibrium, therefore, a condition will bereached in which only one gas tube or similar device will be conducting.

Using the example shown, and assuming that the gas tube in unit number 0has struck, typical values for the voltages of the elements under thepreferred conditions would be as follows:

For the anode'of amplifier number 8 about Volts;

For the lower voltage terminal of the gas tube of unit number 0approximately +60 volts;

For the control grid of amplifier number 0, approximately +2 volts;

For all other control grids, approximately +6.05 volts For all cathodes,approximately +6 volts.

It will be understood that these and other values given are not intendedto limit to the particular values, but merely to serve as examples.

Since the system is perfectly symmetrical, it will be understood that itwill have ten stable states, or one corresponding to each unit in thering, if the number of units is other than ten. In each one of thesestable states one of the devices having sharp cut-01f will be conducting(that is,

7 Where gas lamps are used, one of the lamps will be lit).

Assuming that unit number is operating and gas tube number 0 is lit, andthat the interval since the last count has been sufficient to permit allcapacitors substantially to reach equilibrium, and that a new inputimpulse is applied to input terminal 60, it will be evident that thisimpulse will be transmitted through resistors Bl to the control grids ofall of the amplifiers in the ring, tending to drive all control grids ina positive direction and tending to drive all anodes in a negativedirection. The anode of the amplifier (triode) number 0 is driven to amuch lower voltage (possibly of the order of 35 volts), and the gas tubeor other similar device in unit number 0 ceases to conduct, while thelower voltage side of this gas tube or other device drops very sharplyin voltage (from approximately 60 volts to about 2 volts). voltageapplied through the resistors 51 from the lead 55 at the lower voltageterminal of the gas tube or similar device in unit number 0 willinfluence the control grids of the amplifiers of all other units of thering, partially offsetting the positive change from the input impulsewhich is being counted. At the same time the lower voltage terminal ofthe gas tube or similar device of unit number 0 is also connectedthrough a resistor 58 and capacitor 59 in series to the control grid ofthe amplifier in unit number 1, and the sharp negative change at lead55, transmitted in this way to this control grid, more than offsets thepositive change due to the input impulse, so that the net eifect uponthe control grid of the amplifier of unit number 1 is negative, itsanode rises to a high voltage (possibly of the order of 150 volts) andcauses conduction of the device having sharp cut-off (gas tube) in unitnumber 1.

It will thus be seen that the input impulse is amplified and inverted bythe amplifier of unit number 0 in the way characteristic of vacuum tubeamplifiers and that this amplified impulse is transmitted through thegas tube of unit numher 0 and through the resistor 58 and capacitor 59in series to the control grid of the amplifier in unit number 1.

For best results the time constant of the resistor 58 and capacitor 59is long as compared with the duration of the input impulse, althoughoperation is possible with a time constant equal to or slightly shorterthan the duration of this impulse. Because of this time constantrelation, the voltage transmitted in this way is effective until afterthe termination of the input impulse. The current flowing through thelamp or similar device in unit number 1 is then effective as previouslydescribed to hold the voltage of all other gas tubes below the strikingvoltage, causing the gas tube in unit number 0 to extinguish, and allother gas tubes in the remaining units to remain extinguished.

It is required for operation of the device that the interval betweenimpulses be sufficient so that all condensers can substantially reachequilibrium condition before the arrival of the next impulse. Thesuccessive impulses then function in the same way to transfer thecondition of conduction or striking from one gas tube or similar deviceto the next in the order of the count as predetermined by the connectionbetween the lower voltage terminal of each gas tube and the control gridof the next amplifier through the resistance and capacitor in series.When the The removal of this positive sequence of operations has causedconduction of gas tube 34 in unit number 9, the next succeeding impulseto be counted will actuate unit number 0 in exactly the same manner asthe count is transferred from any one of the previous units to the nextunit of the ring.

It will be evident that at any position, the count in the particulardecade will be indicated by the lighting of a particular gas tube, andthat, where desired, if some other device having sharp cut-off be usedinstead of a gas tube, the particular decade may be provided with otherindicating means, or with a gas tube used purely as an indicator, orwhere indication is not required, this function may be dispensed with.

I have indicated by a fragment of Figure 1 shown in Figure 1*, thenumber 0 unit which would be employed in case a diode rectifier wereemployed as a device having sharp cut-off, instead of the gas tube 25 asin Figure 1. In this case it would be desirable to employ additionalresistors as shown, resistor 63 being interposed between the positivehigh voltage source and the cathode of the diode, and resistor 64 beingconnected between the cathode of the diode and the control grid of eachother amplifier, through the resistors 57 before referred to, and alsoto the control grid of the next amplifier in the sequence through theresistor 58 and capacitor 59. The anode of the diode is connecteddirectly to the anode of the triode as shown. All of the other units ofthe decade will be modified in the same way,

It will be understood of course that in case a diode rectifier wereemployed as shown, the com stants of the circuit would be suitablyadjusted and particularly the value of the cathode bias resistor 53would be suitably increased, preferably to a value of the order of 4000ohms.

It will be understood that in case some other type of device havingsharp cut-off be used, as for example a copper oxide or seleniumrectifier or a crystal detector, the circuit of Figure 1 might beemployed with suitable modification in the circuit constants.

It will be understood that the decade of Figure 1, or any suitablecounting ring embodying the circuit of Figure 1, can be employed as aunit with similar counting rings, or with counting rings of any othersuitable design, as for example those shown in the prior art. For thesake of uniformity in operation, however, it is preferred to employsuccessive decades or other counting rings each embodying the circuitdesign as shown in Figure 1, operatively connected to any suitableexternal circuit for actuation or influencing of external operations,when a particular count is reached. I have, however, developed a noveland preferred external circuit arrangement which is believed to givebest results when used with counting rings of the type illustratedherein, namely those having a single indicator for each step of advance.

In many cases it is desirable to arrange a counting ring or series ofcounting rings so that an external circuit or other mechanism willoperate when the number of impulses received equals a preselected total.Normally where decades are used, one corresponding to units, one totens, one to hundreds, one to thousands, etc., a preselected unit ineach decade of the system would be in operation when the preselectednumber is reached, and at that time it would be desirable to operate theexternal circuit or the like.

This result can be accomplished as shown in Figure 2 by providingindividual selector switches, one for each decade. Thus in this figure aselector switch unit 65 is provided for the units decade, a switch unit66 for the tens decade, and a switch unit 61 for the hundreds decade anda switch unit 68 for the thousands decade. Each switch is provided withcontacts 69, one of which is connected to the anode 41 of each of theamplifiers of the particular decade. By movement of the switch arm 10,it is then possible to select the particular unit of the decade whichwill operate the remote circuit in cooperation with other preselectedunits in the other decades. All of the preselector switches areconnected together at H through resistors 12 and diodes 13, the cathodesof the diodes being connected to the resistors. The anodes of the diodes73, connected together at H, are connected with the control grid 14 of avacuum tube amplifier 15 having a cathode 16 and an anode 11. Thecathode 16 is grounded through a cathode bias resistor 18 and a cathodebias is further maintained by the resistor 19 which connects the cathodeto the positive high voltage direct current supply (suitably at about350 volts).

The resistors 18 and i9 maintain such a cathode bias of the amplifier 15that it is approximately half way between the voltage of an anode of anamplifier in the counting ring when the associated gas tube of that unitis striking, and a similar amplifier when the associated gas tube is notconducting. A resistor 80 is connected between the control grid 14 andthe cathode 76.

The value of the resistor 80 in relation to the resistors 72 which arein series between the selector switches and the diodes 13 will be soselected as to maintain the control grid M at a voltage that will outoff all current through the amplifier 75 when any one of the selectorswitches 65 to 63 is connected to a unit of a decade in which the gastube or other similar device is not conducting. A suitable set of valuesfor illustrative purposes might be as follows:

Triode 15, type 6F5;

Diode 13, one diode unit of type BALS; Resistor T2, 2.2 megohms;

Resistor 80, 2. megohms;

Resistor 18, 25000 ohms;

Resistor 79, 72000 ohms.

In circuit with the anode 18 I provide a relay 8!, which for conveniencein illustration has been shown as a magnetic relay, but may of course bean electronic relay, or impulse generator, or other type as desired.

It will be evident that when and only when all preselector switches arein contact with units of decades which contain gas tubes or similardevices which are conducting, the amplifier 75 will be in a conductingstate, passing current through the magnet coil of relay BI, and closingcontacts 82 and 83. Contacts 32 closethe circuit to apply a necessaryvoltage between terminal 84 suitably at minus 100 volts, and the controlgrid 48 of the amplifier in unit number of each counting ring.Connection with the control grid 48 of the amplifier of unit number 0 ofeach of these rings is provided through a resistor 85, a commonconnection 85 and one of the preferably substantially equal resistors 87to terminals 88 connected to control grids 56 in units number T of eachcounting ring by connections not shown.- Intermediate between theresistor and thegindividual resistors 81, connection to ground isprovided through capacitor 85, and a separate connection to ground isprovided through resistor 90. The capacitor 89 and resistor 90 areintended to eliminate undesired impulses from vibration of the contactsof the relay. It will be evident that as soon as the terminals 82 areclosed, a negative voltage will be applied to the control grid of theamplifier in unit number 0 of each counting ring, driving it in anegative direction, driving the anode of that amplifier in a positivedirection and causing gas tube number 0 to strike. When gas tube number0 strikes it functions as previously described to extinguish any othergas tubes which may be lit and prevent any other lamps from striking.Thus the counter is reset to zero, since the 0 lamp 25 is lighted.

In order to assure or" adequate time for resetting, the relay ti willdesirably be of a slow release type, so that the contacts 82 will bemaintained closed for a perceptible time. Interaction between the gridsof amplifiers of unit number 0 of the various decades is prevented bymaking the values of resistors 8? high compared with the value ofresistor 9E2. The capacitor 89 also aids in preventing such interaction.

It will be evident that the operation of an external device or closingof an external circuit as required, may be accomplished by closing thecontacts 83 in the relay at the same time that the contacts 82 areoperated. Thus when the preselected count is reached, recordingmechanism may be actuated, alarm or indicating devices may be put inoperation, or operations may be performed in connection with automaticmachinery or otherwise.

It will be understood that where desired the automatic reset feature maybe eliminated or the contacts 82 or a parallel set of contacts such as apush button may be closed by hand where this is advantageous.

It will be further understood that the diode 73 is not essential tooperation of the circuit, and that with suitable adjustment of impedancevalues it could be eliminated and the switch arm 10 could be connectedto the lead H with only resistor E2 in series, but that the inclusion ofdiode it allows a greater variation in impedance values, and permitschanging the number of'decades at will without altering the impedances.

It may be desirable in some cases to employ several preselectioncircuits as shown in Figure 2 on a single counter.

When any decade has completed its cycle, and normally at the time thatunit number 9 is passing out of operation and unit number 0 is beingactuated, the sharp up-swing in voltage of the anode of the amplifier inunit number 0 may be used to generate an impulse to advance thefollowing decade by one step. A typical manner in which this may beaccomplished is shown in Figure 3. The sharp up-swing in voltage of theanode 4? of the amplifier of unit number 0 whenthe counting transfer isfrom 9 to 0 is transmitted through condenser 9! across resistor 92 andto the anode of vacuum tube diode 93.

It is further transmitted through the diode 9-3 to the input terminal @0of the following decade.

It will be evident that the duration of this impulse will depend on thevalues of the resistor and condenser in Figure 3. For illustrativepurpose suitable values may be as follows:

Condenser T8, 300 micro-microfarads; Resistor $2, 2.2 megohms; Qipde 3,one'd-iode section oitype GALE).

It will be further evident that when the count passes from to 1 a,negative impulse will pass from the anode of the amplifier of unitnumber 0 through capacitor 9| across resistor 92 and to the anode ofdiode 93 but this impulse is blocked from reaching the following decadeby the diode 93.

Figure 4 illustrates a modified construction of a counting ring whichmay be used where glow discharge lamps of fairly uniform characteristicsare available. The individual units of the counting ring includeamplifiers 94 to I03, inclusive, one in each unit, and desirably formingparts of twin triodes, as well as gas tubes I04 to H3, inclusive. Theamplifiers have anodes II4, cathodes I I5 and control grids I I6. Forthe purpose of simplification, heaters and heater circuits which areused have been eliminated from the drawing. The amplifiers may desirablybe twin triodes of type TF7. The individual anodes are connected to thepositive high voltage direct current source at I I! through desirablysubstantially equal anode load resistors H8. The cathodes are connectedindividually to the higher voltage side of the glow discharge tubes I04to H3, at II9, the lower voltage sides of such tubes at I20 beingconnected together and through a common cathode bias resistor I2I toground. The cathodes are also individually connected through desirablysubstantially equal resistors I22 to a common connection I22 desirablymaintained at a positive voltage intermediate between the positive highvoltage source at In and the ground potential. The control grids areconnected to this same source through individual desirably substantiallyequal resistors I23. Each control grid is connected to the anode of theprevious amplifier through one of the desirably substantially equalcondensers I24.

Input of impulse to be counted in accomplished through the terminal I25and the capacitor I26.

By way of example, suitable values of the impedences and the voltagesare as follows:

Positive high voltage, approximately 200 volts;

Intermediate positive voltage, approximately '75 volts;

Resistor II8, 100,000 ohms;

Resistor I2I, 15,000 ohms;

Resistor I23, 150,000 ohms;

Capacitor I24, 5,000 micro-microfarads;

Capacitor I26, 1 microfarad.

If no gas tubes are lit, all anodes will be at approximately 198 volts,all"cathodes of the triodes at about 80 volts, and the lead I21 commonto the low voltage terminals of the gas tubes will be at approximatelyzero volts. If any gas tube strikes, assuming that it burns atapproximately 60 volts, it will raise the potential of lead I21 to anintermediate voltage, possibly of the order of 16 volts, and will lowerthe voltage across the other gas tubes by approximately 16 volts. If allgas tubes in the counting ring have burning voltages of less than theorder of 60 volts and the lowest striking voltage of any gas tube in thedecade is of the order of say 5 volts above the highest burning voltageof any other gas tube in the counting ring, it will then be possible forany gas tube, once it has lighted, to continue to burn and prevent allother gas tubes from striking until a new impulse is received. When anygas tube is lighted, the current flowing through that gas tube actswith'its associated amplifier and its anode load resistor to lower theanode voltage of that amplifier. Accordingly, when ages tube strikes, anegative impulse is transmitted through the capacitor I24 of that unitto the control grid of the following amplifier. This negative impulsehas little effect because the next amplifier is already nearly atcut-off. As soon, however, as the capacitor I24 has assumed the newcharge, the circuit is ready to respond to a new input impulse. When theinput impulse arrives at the terminal I25 it drives lead I21 positiveand extinguishes the gear tube which was previously lighted. This causesa large positive impulse to be transmitted to the control grid of thenext amplifier, driving its cathode far enough positive to strike thegas tube in its unit. The input impulse duration is preferably shortcompared with the time constant of the capacitor I24 and the resistorsH8 and I23 for the particular unit' connected as shown, and thereforethe gas tube remains lit when the input impulse subsides, and preventsthe previous gas tube in the cycle from relighting. If desired, however,the input impulse duration may be slightly longer than the said timeconstant.

It will be evident that the reset, coincidence and presetting circuits,and the means for passing on the impulse to the next decade, may beconveniently modified to employ this decade instead of the decade ofFigure 1, where it is desired to substitute the counting ring of Figure4.

In view of my invention and disclosure variations and modifications tomeet individual whim or particular need will doubtless become evident toothers skilled in the art, to obtain all or part of the benefits of myinvention without copying the process and apparatus shown, and I,therefore, claim all such insofar as they fall within the reasonablespirit and scope of my claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In an electronic counter, a counting ring having in each unit adevice with a sharp voltage cut off at which current ceases to flow andan amplifier, means including each of the devices with a sharp voltagecut-off at which current ceases to fiow when it is conducting forfeeding a voltage from the amplifiers of each one of the units to eachother unit for rendering the sharp cut off devices in the other unitsnon-conducting and means including unit transfer impedance fortransferring an impulse from the amplifier of one unit to the amplifierof the next unit.

2. In an electronic counter, a counting ring having in each unit anamplifier provided with an anode, a cathode and a control grid and adevice having a sharp voltage cut off at which current ceases to flow,means for maintaining the cathodes of all of th amplifiers at the samepotential, means including each of the devices with a sharp voltage cutoff at which current ceases to flow when it is conducting for feeding avoltage from the amplifiers of each of the units to each other unit forrendering the sharp voltage cut off devices in the other unitsnon-conducting, and means including unit transfer impedance fortransferring an impulse from the amplifier of one unit to the amplifierof the next unit.

3. In an electronic counting ring, having a plurality of unitsoperatively interconnected, an amplifier provided with an anode, acathode and a control grid in each unit, a device having a sharp voltagepoint at which current ceases to flow in each unit interposed in thecircuit between the outputof each amplifier and the control grid ofevery other amplifier except that amplifier, means including each of thedevices having a sharp voltage point at which current ceases to fiowwhen it is conducting for feeding a voltage from the amplifiers of eachone of the units to each other unit for rendering the devices having asharp voltage point at which current ceases to flow in the other unitsnon-conducting and means including unit transfer impedance fortransferring an impulse from the amplifier of one unit to the amplifierof the next unit.

4. In an electronic counting ring, having a plurality of unitsoperatively interconnected, an amplifier provided with an anode, acathode and a control grid in each unit, a cathode grounding resistorthrough which the cathodes of all amplifiers are connected to ground, adevice having a sharp cut off voltage at which current ceases to fiow ineach unit interposed in the circuit between the anode of each amplifierand the control grid of every other amplifier except that amplifier,means including each of the devices having a sharp cut-off voltage whenit is conducting for feeding a voltage from the amplifiers of each oneof the units to each other unit for rendering the devices having a sharpcut-ofi voltage in the other units non-conducting and means includingunit transfer impedance for transferring an impulse from the amplifierof one unit to the amplifier of the next unit.

5. In an electronic counting ring, a plurality of units operativelyinterconnected having an amplifier provided with an anode, a cathode anda control grid in each unit, a cathode grounding resistor through whichthe cathodes of all amplifiers are connected to ground, a series of gridresistors for each unit, a devic having a sharp out off voltage at whichcurrent ceases to fiow for each unit interposed in the circuit betweenthe anode of each amplifier and the control grid of every otheramplifier except that amplifier, one of the grid resistors being locatedbetween the device having sharp out ofi and the control grid of eachother amplifier, a sharp cut off device grounding resistor interposedbetween each device having sharp out off on the side towards the controlgrids and ground, and means including unit transfer impedance fortransferring an impulse from the amplifier of one unit to the amplifierof the next unit.

6. In an electronic counting ring for counting impulses from a source aplurality of units operatively interconnected having an amplifierprovided with an anode, a cathode and a control grid in each unit, acathode grounding resistor through which cathodes of all amplifiers areconnected to ground, a series of grid resistors for each unit, a devicehaving a sharp cut ofi" voltage at which current ceases to fiow in eachunit interposed in the circuit between the anode of each amplifier andthe control grid of every other amplifier except that amplifier, therebeing one of the grid resistors located between the device having sharpcut off and the control grid of each other amplifier, a sharp cut offdevice grounding resistor interposed between each device having sharpcut off on the side toward the control grids and ground, an impulseresistor interposed between the source of the impulse to be counted andeach control grid and a unit transfer resistor and capacitor interposedin series between each sharp cut off device on the side toward thecontrol grids and the control grid of the next unit.

7. In an electronic counting ring for countin impulses from a source, aplurality of units operatively interconnected having an amplifierprovided with an anode, cathode and a control grid in each unit, acathode grounding resistor through which the cathodes of all amplifiersare connected to ground, a series of grid resistors for each unit, adevice having a sharp out off voltage at which current ceases to flow ineach unit interposed in the circuit between the anode of each amplifierand the control grid of every other amplifier except that amplifier,there being one of the grid resistors located between the device havingsharp cut oif and th control grid of each other amplifier, a sharp cutofi device grounding resistor interposed between each device navingsharp cut off on the side toward the control grids and ground, animpulse resistor interposed between the source of the impulse to becounted and each control grid and a unit transfer resistor and capacitorinterposed in series between each sharp cut off device on the sidetoward the control grids and the control grid of the next unit, the unittransfer resistor and capacitor in series having a time constantsubstantially greater than the duration of the impulse to be counted.

8. In an electronic counting ring, a plurality of units operativelyinterconnected having an amplifier provided with an anode, a cathode anda control grid in each unit, a gas tube in each unit interposed in thecircuit between the output of each amplifier and the control grid ofevery other amplifier except that amplifier, means including each of thegas tubes when it is conducting for feeding of voltage from theamplifiers of each one of the units to each other unit for rendering thegas tubes in the other units nonconducting and means including unittransfer impedance for transferring an impulse from the amplifier of oneunit to the amplifier of the next unit.

9. In an electronic counting ring, a plurality of units operativelyinterconnected having an amplifier provided with an anode, a cathode anda control grid in each unit, a cathode grounding resistor through whichthe cathodes of all amplifiers are connected to ground, a gas tube ineach unit interposed in the circuit between the anode of each amplifierand the control grid of every other amplifier except that amplifier,means including each of the gas tubes when it is conducting for feedingof voltage from the amplifiers of each one of the units to each otherunit for rendering the gas tubes in th other units non-conducting andmeans including unit transfer impedance for transferring an impulse fromthe amplifier of one unit to the amplifier of the next unit.

10. In an electronic counting ring, a plurality of units operativelyinterconnected having an amplifier provided with an anode, a cathode anda control grid in each unit, a cathode grounding resistor through whichthe cathodes of all amplifiers ar connected to ground, a series of gridresistors for each unit, a gas tube in each unit interposed in thecircuit between the anode of each amplifier and the control grid ofevery other amplifier except that amplifier, there being one of the gridresistors located between the gas tube and the control grid of everyother amplifier, a gas tubeig rounding resistor interposed between eachgas tube on the side toward the control grids and ground, and meansincluding unit transfer impedance for transferring an impulse from theamplifier of one unit to the amplifier of the next .unit.

11. In an electronic counting ring for counting impulses from a source,a plurality of units operatively interconnected having an amplifierprovided with an anode, a cathode and a control grid in each unit, acathode grounding resistor through which cathodes of all amplifiers arconnected to ground, a series of grid resistors for each unit, a gastube for each unit interposed in the circuit between the anode of eachamplifier and the control grid of every other amplifier except thatamplifier, there being one of the grid resistors located between the gastube and the control grid of each other amplifier, a gas tube groundingresisto interposed between each gas tube on the side toward the controlgrid and ground, an impulse resistor interposed between the source ofthe impulse to be grounded and each control grid and a unit transferresistance and capacitor interposed in series between each gas tube onthe side toward the control grids and the control grid of the next unit.

12. In an electronic counting ring, a plurality of units operativelyinterconnected having an amplifier limited to a single anode, cathodeand control grid in each individual unit, a gas tube in each unitinterposed in the circuit between the output of each amplifier and thecontrol grid of every other amplifier, means including each of the gastubes when it is conducting for feeding of voltage from the amplifiersof each one of the units to each other unit for rendering the gas tubesin the other units non-conducting and means including unit transferimpedance for transferring an impulse from the amplifier of one unit tothe amplifier of the next unit.

13. In an electronic counting ring, a plurality of units operativelyinterconnected having an amplifier limited to a single anode, cathodeand control grid in each unit, a cathode grounding resistor throughwhich the cathodes of all amplifiers are connected to ground, a gas tubein each unit interposed in the circuit between the anode of eachamplifier and the control grid of every other amplifier, means includingeach of the gas tubes when it is conducting for feeding of voltage fromthe amplifiers of each one of the units to each other unit for renderingthe gas tubes in the other units non-conducting and means including unit16 transfer impedance for transferring an impulse from the amplifier ofone unit to the amplifier of the next unit.

14. In an electronic counting ring for counting impulses from a source,a plurality of units operatively interconnected having an amplifierlimited to a single anode, cathode and control grid in each unit, acathode grounding resistor through which the cathodes of all amplifiersare connected to ground, a series of grid resistors for each unit, a gastube in each unit interposed in the circuit between the anode of eachamplifier and the control grid of every other amplifier, there being oneof the resistors located between the gas tube and the control grid ofevery other amplifier, a sharp cut oil device grounding resistorinterposed between each gas tube on the side toward the control gridsand ground, an impulse resistor interposed between the source of theimpuls to be counted and each control grid and a unit transfer resistorand capacitor interposed in series between each gas tube on the sidetoward the control grids and the control grid of the next unit.

WILLIAM ANTHONY GEOHEGAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,266,862 Hardey Dec. 23, 19412,310,105 Michel Feb. 2, 1943 2,405,66 Mumma Aug, 13, 1946 2,411,714 DeRosa Nov. 26, 1946 2,427,533 Overbeck Sept. 16, 1947 2,441,006 CanforaMay 4, 1948 2,462,275 Morton et al. Feb. 22, 1949 FOREIGN PATENTS NumberCountry Date 572,884 Great Britain Oct. 29, 1945 OTHER REFERENCESElectrical Counting by W. B. Lewis; pp. -92; published by the MacMillan00., New York, 1943.

